Please keep in mind the ESRL/PSD GSDM web link, below, while reading this discussion.
The 91-day signal to noise ratio (snr) anomaly composites are currently centered on 23 November due to technical issues. There are also numerous other delayed real-time products such as the AAM plots and vector wind animations. We hope these problems will be resolved soon. WB (2009; likely not to be published until next year), part-1 of a 2 part paper where the GWO is formally introduced, is in press for MWR publication. There is a link in the Appendix to download the manuscript.
Please remember that these discussions are part of an experimental effort involving linking weather and climate. Until this work is formalized at the national level, many important scientific issues we are easily well aware of cannot be addressed. Stated another way, it is nearly impossible for me to talk about “everything” in these postings, including offering attribution to unpredictable noise. Also, plans are moving forward to have a one-day workshop on the WB (2009) GWO concepts during February 2009 in
There is little overall change in the spatial pattern of global SSTs. The warmest waters extend from north of
How much additional SST cooling that occurs in all Nino regions is unclear. However, there has been a decided tilt toward La-Nina for at least the last 3-4 weeks, responding to a global circulation (interacting with the global oceans and land masses) that has been exhibiting those same characteristics arguably since boreal spring 2007.
http://www.cdc.noaa.gov/forecast1/IndoPacific.frcst.html (note the initial projection)
There is no change from the scientific matters discussed in my long 22 November 2008 “treatise”. Lack of up to date AAM/GWO and related plots will also limit this writing.
Tropical convective forcing has shifted east to ~0/130-140E essentially covering most of
Intense to severe thunderstorm activity across tropical
While there is a MJO component to the
In fact, reconstructed Hovmollers utilizing the WH (2004) RMMs show generally greater than 10m/s westerly wind flow anomalies at 200mb across the
If updated, I suspect that global relative AAM is still a good standard deviation above the R1 data climatology, and that the AAM tendency signal will not be that strong. In other words, the WB (2009) measure of the GWO may be undergoing a fast variation (looping) in octants 7-8-1 of phase space. The extended North Pacific jet/split flow situation this past week across North America was one synoptic response (giving
Directly linked to the
For the past 5-6 weeks I have offered the notion of some form of an 8-1 transition in WB (2009) GWO phase space followed by a December cold regime focused on the middle of the
This only reminds us of the enormous work that is always needed involving linking weather and climate, especially when dealing with red noise dynamical processes represented by the WB (2009) measure of the GWO. These forecast "busts" also offers opportunities to learn. However, I do emphasize these are probabilistic statements, and synoptic notions are presented “to communicate” the best information possible to weather sensitive users. These blog discussions are not very efficient to optimize weather-climate “insights” that can be given by the WB (2007, 2009) dynamical framework (ex., subseasonal “maps” and plume diagrams with real-time live discussions would be far more effective).
I suspect during the next 1-2 weeks the Western Hemisphere wind signal, explained by the WB (2009) measure of the GWO, will come back into the Eastern Hemisphere and excite intense tropical convection across the
An evolution shown by phases 8-1 of the GWO 250mb snr streamfunction composite anomaly plots is likely week-1. That translates to the discontinuous retrogression discussed above of the west coast ridge leading to trough amplification across the
As the tropical forcing returns to the
Regardless of the details, I do think it is probable to have a global circulation best represented by ~phases 2-4 of the GWO and MJO 250mb snr composite psi anomaly plots by the latter half of December. Synoptically across the PNA sector, this suggests a continued westward shift of extratropical circulation anomalies with the ridge perhaps to ~150W and troughs initially impacting the
Internationally, intense to severe rainfall is likely to continue across much of tropical South America including Brasil week-1 shifting into
Please see the latest official tropical cyclone forecasts for all basins. Currently that risk is unclear. I trust the expertise of the appropriate meteorological centers to alert the public of additional weather hazards worldwide. For instance, more strong troughs are digging into western Europe.
Links to CPC and PSD ENSO discussions:
The following is a link to information about the stratosphere and other nice monitoring tools:
The following is a link to NCEP model verifications (surf around for lots more)
The following is a link discussing recent global weather and related events:
These are probabilistic statements. We hope that an opportunity will arise for us (soon) to allow our dedicated web page effort to mature, expediting objectively and accountability. This web page effort will hopefully include an objective predictive scheme for the GWO with hindcasts.
The WB (2007) paper on the GSDM has been published in the February issue of MWR. The first of a two-part paper, where WB formally introduce the GWO (WB (2009)), has been accepted for publication MWR. A pdf of the in press version can be downloaded from the following link:
In addition to the subseasonal snr composite anomaly plots, we hope near real-time discussions with “weather maps” will become a routine part of the ESRL/PSD GSDM web site sometime soon. Part-2 of our GWO paper will discuss the latter. We want to emphasize notions such as global-zonal mean-regional scale linkages as well as forcing-response-feedback (with subsequent interactions) relationships. An important purpose is to provide a dynamical weather-climate linkage framework to evaluate the numerical models in a sophisticated manner as part of a subseasonal (and any time scale) forecast process, in addition to a climate service for all users. Relying on the numerical models alone is a cookbook! I plan on posting a discussion the weekend of 6-7 December.